4th Exam: Pediatric Pathology Flashcards
Case: blue baby born at 37wk, resp stridor (difficulty), cyanosis, heart murmur, uneventful pregnancy and delivery, healthy 3yo at home
Tetralogy of Fallot
Case: 6yo boy, large, weak calves, began tripping and stumbling at 3yo, weakness of arms/thighs at age 4, serum ck elevated 1200 u/l (normal 100) – from muscle (not heart), Gower’s maneuver to stand, brother died at age 12 from same disease
Duchenne’s Dystrophy
Case: baby w large abdomen, 2 yo boy, recently losing weight, 100F fever, low energy, abdominal mass, lab: elevated urinary HVA (catecholamine)
Neuroblastoma
S-W syndrome sf:
Sturge-Weber Syndrome (malformation of caps)
S-W syndrome:
congenital, nonfamilial, born w capillary vascular malformation, too many caps in skin, mouth (port wine stain), facial lesions, usually unilateral, only 10% of pts w port wine stain have S-W (bc it spec includes brain involvement), in one or more divisions of CNV, may involve meninges of brain, seizures
S-W Oral Lesions:
Common, not inflammation, but a vascular malformation, gingiva, buccal mucosa
Do S-W lesion expand or contract?
No
Malformation in S-W lesion consists of:
numerous dilated, proliferations of caps in dermis or submucosa
Congenital Heart Disease:
disturbance in heart formation in utero, many causes and types, 1% of live births, many can be corrected by surgery, inc incidence in adults
Risk factors for CHD:
Chromo abnormalities (Down’s), molecular abnormalities, maternal status: meds, infections (rubella), diabetes
Tetralogy of Fallot (4):
Most common cyanotic heart disease (most common cause of blue baby), VSD (no inter-ventricular septum), pulmonary artery stenosis/ narrowing, flow into lungs restricted, deoxygenated venous blood pumped into systemic circulation, RV gets huge, under pressure, work related hypertrophy, heart murmur, R to L shunt, pt cyanotic, tissues oxygen deprived, hole bw R and L heart → pressure (systolic pressure in baby) is equal between two ventricles (right is higher than normal pressure) → O2 pressure is low and almost equal (60%: RV, 70%: LV) → deoxy blood is going into the L heart
Tetralogy Physiology to the body:
Deoxygenated blood shunted from R to L, systemic flow now dec in O2, pt blue (cyanotic) as tissues are O2 deprived
Surgery for Tetralogy of Fallot:
Close VSD, open narrowed pulm a., (relieve stenosis, stop communication bw V’s)
Muscular Dystrophies:
“faulty nutrition”, heterogeneous disease group (~20)(Duchenne’s, LGMD (Limb-Girdle muscular dystrophy), MyD (myotonic dystrophy), etc.), familial, early onset (1st 5 yrs), usually not present at birth, progressive, never improves, severe weakness, skeletal muscle disease
Duchenne Muscular Dystrophy (DMD):
X linked recessive, boys, X chromo, site 21, must have total deletion of dystrophin gene (makes protein), onset: 2-5yo, poor prognosis – often die of heart disease in early 20’s
DMD symptoms:
Gower’s maneuver, calf pseudohypertrophy, diagnostic, enlarged, weak, fatty, fibrous infiltration, proximal muscle weakness (trunk) and proximal extremities
DMD muscle & heart disease:
hyper-contract, see spaces around them… pre necrosis “pre-hyaline fibers”, pre-necrotic hyaline fibers (pink, rounded), necrotic fibers → macs/phagocytosis, centered nuclei, cardiac fibrosis → heart failure
Pathology of DMD, “delta lesion”:
Dystrophin: stabilizes mem, mem assoc protein, prevents rupture during contraction, dystrophin gene deleted from X chromosome, cant make dystrophin, unstable muscle membrane, tiny ruptures in membrane → Extracellular Ca2+ influx → protease activation → death, muscle fibers die, pt becomes weak
Neuroblastoma
50% infant tumors, 10% of childhood tumors, median age at dx: 22mo (2 years), molecular abnormalities, abnormalities of N-myc (oncogene), chromosome 2p23, amplification of N-myc = poor prognosis, neural tumors, secrete catecholamines: dopamine, epinephrine, NE, catecholamines in urine, diagnostic, HVA and VMA: metabolic products of catecholamines, EM: secretory granule, neuroendocrine tumors
PNETs sf:
Primitive Neuroectodermal Tumors
PNETs:
Family of neuroendocrine tumor,small cell carcinoma of the lung (a small cell blue tumor), Neural markers on cells, usually children, all secrete something enlarged abdomen,, neuroblastoma, Medulloblastoma – brain, rentinoblastoma – eye, ewing’s sarcoma – bone
Neuroblastoma Pathology (the tumors):
Often arise in adrenal medulla, malignant, grossly soft, bulky, necrotic, hemorrhagic, composed of primitive cells (PNET), embryologic neural crest derivative, small, blue, round cell tumors, many mitoses, necrosis – necrotic tumor coming from adrenal gland, cells may differentiate into neurons (good prognosis), form rosettes = neuronal differentiation
Neuroblastoma Behavior:
55% 5y survival, < 2yo: 80% 5y survival (higher for infants), N-myc amplification - poor prognosis, some spontaneously regress, very unusual in mal tumors, some differentiate into neurons = good px, metastasis to (BELL) bone, eye, liver, lungs, 60% of kids present w metastasis
Histology of neuroblastoma:
Cellular, sea of small round blue cells, necrosis, many mitoses, rosettes = neuronal differentiation, secretory granules on EM, neuroendocrine granules
Neuroblastoma = Neuroendocrine Tumor:
Secretes catecholamines, found in urine, diagnostic, look for metabolites of catecholamines: HVA – homovanillic acid, VMA – vanillylmandelic acid
TF? Most kids w port-wine stain have S-W syndrome.
F.
Oral mani of S-W syndrome:
hyperemia of B mucosa
TF? The S-W lesion will grow in time.
F. not a tumor
TF? The R V is under systemic pressure in the tetrolagy of Fallot (TOF):
T.
How do P and O2 content vary bw LV and RV in TOF?
100 P in both, 60% oxygenated in RV, 70% in LV
TF? A person born today with TOF will most likely only survive until the age of 20.
F we can open pulm a. and patch VSD.
What part of the cell is affected in Duchenne muscular dystrophy?
cell membrane
Cause of death for most pts w Duchenne’s muscular dystrophy:
severe heart disease, fibers necrose, hypercontracted, fibers die gradually, not all at once, macs come into to digest, tries to regenerate, can’t keep, up, smaller and weaker over time
W/o dystrophin, what will happen to a cell when it contracts?
it will tear holes in the membrane, Ca enters, activates protesases that kills the cell
Is the px for neuroblastoma better if the pt is young or old?
young
Ex of a tumor that can spontaneously regress;
neuroblastoma (1%)
Classic presentation of neuroblastoma:
metastesis in eye
Origin of tumors:
medulla
50% of kids w a protruded abdomen will have:
neuroblastoma
Origin of neuroblastoma tumors:
center of adrenal medulla
All blue cell tumors make:
rosettes, ring of nuclei around a central focus
What type of tumor is the neuroblastoma?
neuroendocrine tumor
neuroendocrine tumor:
secrete catecholamines, can be found in urine, represents a dx test, look for metabolites like HVA and VMA, EM show secretory granules
Diagnostic of neuroblastoma:
HVA and VMA
